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Subject: [gentoo-user] Portknock before Postfix delivery?
From: Pandu Poluan <pandu@poluan.info>
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I'm just wondering...
I'm implementing an email gateway using postfix. The gateway lives as
a VM in my ISP, and it will deliver 'accepted' emails to the company's
email server which lives in the DMZ. The email server's port is
shifted to a non-25 external port number.
So far so good. However, a portscanner might still be able to detect
which port is open and attempt deliveries there.
So, the question: Is it possible to configure the system in some way
so that Postfix will first perform a portknocking before attempting
delivery to the internal mail server?
If that is not possible, what solution would you recommend to 'harden'
the non-25 mail port?
Rgds,
--
--
Pandu E Poluan - IT Optimizer
My website: http://pandu.poluan.info/